<?php
/**
 * Zend Framework
 *
 * LICENSE
 *
 * This source file is subject to the new BSD license that is bundled
 * with this package in the file LICENSE.txt.
 * It is also available through the world-wide-web at this URL:
 * http://framework.zend.com/license/new-bsd
 * If you did not receive a copy of the license and are unable to
 * obtain it through the world-wide-web, please send an email
 * to license@zend.com so we can send you a copy immediately.
 *
 * @category   Zend
 * @package    Zend_Filter
 * @copyright  Copyright (c) 2005-2011 Zend Technologies USA Inc. (http://www.zend.com)
 * @license    http://framework.zend.com/license/new-bsd     New BSD License
 * @version    $Id: Gz.php 23775 2011-03-01 17:25:24Z ralph $
 */

/**
 * @see Zend_Filter_Compress_CompressAbstract
 */
require_once 'Zend/Filter/Compress/CompressAbstract.php';

/**
 * Compression adapter for Gzip (ZLib)
 *
 * @category   Zend
 * @package    Zend_Filter
 * @copyright  Copyright (c) 2005-2011 Zend Technologies USA Inc. (http://www.zend.com)
 * @license    http://framework.zend.com/license/new-bsd     New BSD License
 */
class Zend_Filter_Compress_Gz extends Zend_Filter_Compress_CompressAbstract {
	/**
	 * Compression Options
	 * array(
	 * 'level'    => Compression level 0-9
	 * 'mode'     => Compression mode, can be 'compress', 'deflate'
	 * 'archive'  => Archive to use
	 * )
	 *
	 * @var array
	 */
	protected $_options = array ('level' => 9, 'mode' => 'compress', 'archive' => null );
	
	/**
	 * Class constructor
	 *
	 * @param array|Zend_Config|null $options (Optional) Options to set
	 */
	public function __construct($options = null) {
		if (! extension_loaded ( 'zlib' )) {
			require_once 'Zend/Filter/Exception.php';
			throw new Zend_Filter_Exception ( 'This filter needs the zlib extension' );
		}
		parent::__construct ( $options );
	}
	
	/**
	 * Returns the set compression level
	 *
	 * @return integer
	 */
	public function getLevel() {
		return $this->_options ['level'];
	}
	
	/**
	 * Sets a new compression level
	 *
	 * @param integer $level
	 * @return Zend_Filter_Compress_Gz
	 */
	public function setLevel($level) {
		if (($level < 0) || ($level > 9)) {
			require_once 'Zend/Filter/Exception.php';
			throw new Zend_Filter_Exception ( 'Level must be between 0 and 9' );
		}
		
		$this->_options ['level'] = ( int ) $level;
		return $this;
	}
	
	/**
	 * Returns the set compression mode
	 *
	 * @return string
	 */
	public function getMode() {
		return $this->_options ['mode'];
	}
	
	/**
	 * Sets a new compression mode
	 *
	 * @param string $mode Supported are 'compress', 'deflate' and 'file'
	 */
	public function setMode($mode) {
		if (($mode != 'compress') && ($mode != 'deflate')) {
			require_once 'Zend/Filter/Exception.php';
			throw new Zend_Filter_Exception ( 'Given compression mode not supported' );
		}
		
		$this->_options ['mode'] = $mode;
		return $this;
	}
	
	/**
	 * Returns the set archive
	 *
	 * @return string
	 */
	public function getArchive() {
		return $this->_options ['archive'];
	}
	
	/**
	 * Sets the archive to use for de-/compression
	 *
	 * @param string $archive Archive to use
	 * @return Zend_Filter_Compress_Gz
	 */
	public function setArchive($archive) {
		$this->_options ['archive'] = ( string ) $archive;
		return $this;
	}
	
	/**
	 * Compresses the given content
	 *
	 * @param  string $content
	 * @return string
	 */
	public function compress($content) {
		$archive = $this->getArchive ();
		if (! empty ( $archive )) {
			$file = gzopen ( $archive, 'w' . $this->getLevel () );
			if (! $file) {
				require_once 'Zend/Filter/Exception.php';
				throw new Zend_Filter_Exception ( "Error opening the archive '" . $this->_options ['archive'] . "'" );
			}
			
			gzwrite ( $file, $content );
			gzclose ( $file );
			$compressed = true;
		} else if ($this->_options ['mode'] == 'deflate') {
			$compressed = gzdeflate ( $content, $this->getLevel () );
		} else {
			$compressed = gzcompress ( $content, $this->getLevel () );
		}
		
		if (! $compressed) {
			require_once 'Zend/Filter/Exception.php';
			throw new Zend_Filter_Exception ( 'Error during compression' );
		}
		
		return $compressed;
	}
	
	/**
	 * Decompresses the given content
	 *
	 * @param  string $content
	 * @return string
	 */
	public function decompress($content) {
		$archive = $this->getArchive ();
		$mode = $this->getMode ();
		if (file_exists ( $content )) {
			$archive = $content;
		}
		
		if (file_exists ( $archive )) {
			$handler = fopen ( $archive, "rb" );
			if (! $handler) {
				require_once 'Zend/Filter/Exception.php';
				throw new Zend_Filter_Exception ( "Error opening the archive '" . $archive . "'" );
			}
			
			fseek ( $handler, - 4, SEEK_END );
			$packet = fread ( $handler, 4 );
			$bytes = unpack ( "V", $packet );
			$size = end ( $bytes );
			fclose ( $handler );
			
			$file = gzopen ( $archive, 'r' );
			$compressed = gzread ( $file, $size );
			gzclose ( $file );
		} else if ($mode == 'deflate') {
			$compressed = gzinflate ( $content );
		} else {
			$compressed = gzuncompress ( $content );
		}
		
		if (! $compressed) {
			require_once 'Zend/Filter/Exception.php';
			throw new Zend_Filter_Exception ( 'Error during compression' );
		}
		
		return $compressed;
	}
	
	/**
	 * Returns the adapter name
	 *
	 * @return string
	 */
	public function toString() {
		return 'Gz';
	}
}
